Applying an electric or magnetic field to some materials may cause the materials to flex or contract. In one example, a structure containing a piezoelectric material may flex in a presence of an electric field. The amount in which the structure flexes may depend on a magnitude of the electric field applied to the piezoelectric material. When the electric field is removed, the structure may become flexible or return to the structure's original shape.
In another example, a structure containing one of a magnetorheological fluid and a shape memory alloy may contract in a presence of a magnetic field. The amount in which the structure contracts may depend on a magnitude of the magnetic field applied to the one of the magnetorheological fluid and the shape memory alloy. When the magnetic field is removed, the structure may become flexible or return to the structure's original shape.